Homo naledi, part 1

Paleoanthropology got front-page (above the fold!) coverage last week with the announcement and initial publication of Homo naledi, a new species of Homo, based on the large assemblage of hominin fossils recovered from the Rising Star Cave, South Africa, in 2013. The fossils, more than 1,500 of them in all, represent one of the largest single locality samples of hominins ever published. That is a big deal. Regardless of whether you agree with the initial scientific conclusions of the research team regarding where this assemblage fits in the human evolutionary story (and I will have more on that later in the week), this is a human evolutionary story worth following. Before I get into the details of the fossils themselves, I want to highlight the process that led to this publication, and why it is such a positive step forward for paleoanthropology.

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The semester just began here at Wellesley, which means I am fresh off several lectures focused on the nature of science and scientific knowledge production. Paleoanthropology, as a science, faces several challenges. One of the first is that paleoanthropology is inherently tied to the material evidence of human evolution. We can (and do) learn a vast amount about the world around us, including our evolutionary origins, through comparative research on living organisms in a contemporary context. But in the end, it is necessary to go back to the fossil record itself to gather direct evidence of our evolutionary past and to test hypotheses about the events that shaped us into the species that we have become. This is a challenge, in part, because most of our evolutionary story is in Africa, and most of the funding for studying human evolution is in North America and Europe. Additionally, paleoanthropology, and particularly the field work side of things, has historically been dominated by male voices (though check out Trowelblazers for amazing stories of pioneering women in the field!). These two items, coupled with the gate-keeping nature of many academic structures, have limited who has access to the basic observational data at the core of paleoanthropology.

The strength of science is that it attempts to be a fully translatable system of knowledge. Given the same set of observations, two informed individuals can reach the same conclusion. This, in turn, allows the knowledge produced by science to be cumulative, leading to further and further refinements about our understanding of the observable world around us. The assumption that two individuals can have access to the same set of observations too often turns out not to be the case in paleoanthropology.

The Rising Star project, organized by the University of Witwatersrand in Johannesburg, was international, inclusive, and conspicuously focused on assisting new voices in our field. Following the initial recovery of materials from the cave, work carried out in large part by six female researchers, the “workshop” that conducted the initial investigation of these materials targeted graduate students and pre-tenure faculty (I got tenure a year too soon!…just kidding). I can’t speak to how this all actually worked out, but these are certainly positive ideals to shoot for. And then there is this…

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The picture above is a 3D model of the UW 101-1261 mandible from the Dinaledi chamber of the Rising Star Cave system. It is part of the type specimen of Homo naledi, and the model is freely available on the open access site, morphosource.org. So here I am, before class, printing it out.

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Paleoanthropology cannot be a science if the only voices involved in shaping the knowledge we produce are the few who have access to the primary observational data. A 3D model like that above cannot replace the “real thing,” and there is still tremendous value in the actual original material itself. That is not going to change. But the ability to conduct good science is immensely aided by enhancing access to the primary data in our field. There have been numerous attempts to increase the level of access to fossil material in paleoanthropology, but I can’t think of anything quite on this scale, in terms of the amount of material made public and speed with which it has been done.

Homo naledi may indeed be a “new branch” on the human evolutionary story. It might tell us exciting new things about the evolution of our lineage. Or maybe it will just re-confirm or solidify things we already know. I don’t know. But given I can directly access a lot of the material directly, within days of the initial publication, in my lab…at least I have the hope of someday knowing.

And by the way…if you are interested in learning more about human evolution, including Homo naledi, check out Anthropology 207x, an open-access course on human evolution! If you do, you will be part of the now more than 30,000 people who have taken part in the course since it debuted two years ago!

About Adam Van Arsdale

I am biological anthropologist with a specialization in paleoanthropology. My research focuses on the pattern of evolutionary change in humans over the past two million years, with an emphasis on the early evolution and dispersal of our genus, Homo. My work spans a number of areas including comparative anatomy, genetics and demography.
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One Response to Homo naledi, part 1

  1. marc verhaegen says:

    Enormous find & excellent work of prof.Berger’s team, but IMO their interpretations are too anthropocentric. It was no intentional burial, but a natural accumulation. Homo or Australopithecus naledi were orthograde swamp-forest or wetland waders-climbers, not unlike bonobos (google wading bonobo) or lowland gorillas who wade bipedally in forest swamps in search of freshwater foods but much more frequently: naledi’s more bonobo-like curved hand bones suggest vertical climbing, and their more human-like flat feet suggest frequent wading (cf plantigrade flamingo vs digitigrade ostrich), possibly in search of hard-shelled invertebrates, sedges, frogbit, waterlilies etc. When they died, their bodies sank in the mud, and when later the underground eroded (cave system), the mud(stone) slid into the cave: apparently there were few other macro-fauna in the swamp then (google gorilla bai).

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